Labour has said questions remain following the decision to close a company owned by Rishi Sunak's wife.
Akshata Murty filed to to close her start-up investment firm, Catamaran Ventures UK, in December.
A spokesperson for the prime minister's wife said the company's holdings would be transferred to charity.
Labour has written to Deputy PM Oliver Dowden raising a number of questions, including what impact the winding up could have on other companies.
Last year the Sunday Times reported that Catamaran Ventures held shares in Study Hall, an education start-up which received a government grant of almost £350,000.
In a letter to Mr Dowden, Labour's national campaign co-ordinator Pat McFadden asked what impact the closure of Catamaran Ventures could have on the government-backed business and any other companies it retained a stake in.
He also asked what the arrangement was for the payment of tax owed to HMRC and whether Catamaran Ventures would be fulfilling all its liabilities to the British taxpayer.
Mr McFadden called for the prime minister and his wife's interests continue to be properly declared in the Register of Ministerial Interests following the decision to close the company.
"It is vital that these questions are answered in the interests of, to quote the prime minister himself, 'integrity, professionalism and accountability'," he wrote.
A spokesperson for Ms Murty said Catamaran Venture's holdings would be transferred to ShareGift, a charity with experience accepting donations in the form of shares.
The spokesperson added: "Ms Murty has shortlisted several charities focused on veterans' affairs and education for the ShareGift team to consider at the time of disbursement."
The decision to wind up the company was previously reported in September and was confirmed in a notice on the London Gazette, the official public record, published on 28 December.
With an election expected this year, Mr McFadden's decision to write to Mr Dowden about Ms Murty may signify Labour's willingness to try to make her and her wealth a factor in campaigning.
Mr McFadden denied the party was trying to create "political capital" out of the issue.
"This is a company that invested in a lot of other companies that were very fortunate in getting help from the taxpayer. And some of them have subsequently gone bust," he told Sky News.
He added that Labour wanted to ensure "everything is properly declared here, as this venture now winds up".
Ms Murty has also shown her own willingness to enter the political fray, introducing her husband before his speech to the Conservative Party conference in October.
The finances of Mr Sunak and his wife previously faced scrutiny when it was revealed Ms Murty had non-dom status, which allows people living in the UK to avoid paying UK tax on money they made abroad.
Following criticism, Ms Murty said she would start paying UK tax on her overseas earnings.
Ms Murty's father founded one of India's biggest companies, Infosys, and she owns shares in the firm worth an estimated £700m.
Catamaran Ventures, which invests in start-ups, was founded by the Sunaks in 2013.
Mr Sunak stood down as a director in 2015 when he became an MP and a year later his wife became a majority shareholder.
