Attempts by Andrea Leadsom to silence critics questioning her City credentials have backfired after fresh holes were discovered in claims about her 25-year career in finance.

The energy minister, who has emerged as a leading candidate to succeed David Cameron, published the official version of her CV on Wednesday in a move her spokesperson said would “comprehensively disprove” allegations that she had been less than clear about her career before entering politics.

But Leadsom’s CV has raised a number of further questions because it omits some company directorships, alters existing claims and fails to clear up question marks over sections of her City career. The issues include:

• Some past roles being omitted from the CV, including Leadsom’s directorship of her family’s buy-to-let company Bandal Limited and Seaperfect, a company connected to her brother-in-law.
• Her job title at Barclays, where she worked in the 1990s, is given as deputy financial institutions director, not — as previously stated — financial institutions director.
• The CV describing her position at a hedge fund run by her brother-in-law, De Putron Fund Management, as managing director while company filings give her role as marketing director.
• Stating she was a senior investment officer at fund management firm Invesco Perpetual for 10 years, though she was only authorised as an investment manager for a three-month period.

As well as omitting mention of her family buy-to-let business, Leadsom’s CV also glosses over her directorship at Seaperfect, a company that invested heavily in clam and scallop farming in Chile and America during the 90s.

However, the company lost millions after the investments failed and her brother in law, Peter de Putron, subsequently took control of the business through an offshore vehicle called Wildernesse Holdings. Leadsom, working under her maiden name of Andrea Salmon, became a director of Seaperfect from February 1998 to May 1999.

Amid questions over Leadsom’s City career, a spokesperson for Invesco Perpetual confirmed Leadsom had been given the job title of senior investment officer, but declined to say whether she had responsibility for managing funds.

One former colleague, who worked with Leadsom at Invesco Perpetual, said he did not believe she made investment decisions. Robert Stephens told the Guardian that she “absolutely, emphatically” had no involvement in controlling funds and that her title was not representative of her responsibilities.

“What does senior investment officer convey to the uninitiated? If you’ve got a chief investment officer, you would think the senior investment is someone with just slightly less responsibility than the chief investment officer. This is totally untrue; she had no investment management responsibilities at all,” he said.

Last week Stephens sent an email to Leadsom asking why her biography on Wikipedia identified her as the chief investment officer of Invesco Perpetual. Leadsom replied, denying that she had made the change, but said that she would check it.

An MP who had worked alongside Leadsom on the Treasury select committee, but asked not be named, said he was concerned the energy minister’s career in finance was being misunderstood. Given she was authorised by the City regulator to manage investments for only a brief period of time, he said: “I don’t think she would have been running money, making [Invesco investment] decisions.”

The MP was equally sceptical of claims that Leadsom had played a significant role helping calm the financial markets after rogue trader Nick Leeson brought down Barings bank in 1995.

The energy minister has previously claimed that, while working at Barclays, she “helped the then governor of the Bank of England, Eddie George, over the weekend that Barings collapsed as he tried to reassure the markets and prevent a run on the banks”. Though an impressive claim, this is not repeated on her CV.

The Treasury select committee MP told the Guardian: “I cannot quite see why a 30-year-old would be in a huddle with Eddie George in the middle of the Barings crisis. Yes, she was there. But David Cameron was photographed behind Norman Lamont [during the Black Wednesday financial crisis in 1992]. That doesn’t mean he played a big role in sorting that crisis out.”

Leadsom has regularly cited her role in the Barings crisis. In May she explained in one newspaper article how such experiences made her confident Brexit would not trigger another financial crisis for the UK. “As someone who spent 25 years working in finance ... I’ve seen at first hand the economic cycles, the disasters and triumphs”. In the article she said she had spent the mid-1990s “running Barclays Investment Banking team”.

A spokesperson for Barclays declined to comment on her role.

Andrew Buxton, who was chairman of Barclays in the mid-1990s and had a leading role in leading the City response to the Barings collapse, said : “She wasn’t a senior manager at the time, it was quite early in her career. But she was well-regarded.

“I honestly can’t remember exactly what her role was: when I say senior manager, she didn’t run the company, but she was senior middle manager, that sort of thing. This was 20 years ago and you can’t judge someone on where they were 20 years ago.”