British Prime Minister Rishi Sunak's register of ministerial interests was published by the UK Cabinet Office on Wednesday, revealing his wife Akshata Murty's shares in a childcare agency which could benefit from a policy in last month's Budget.

The publication of the list came in the wake of a parliamentary watchdog probe opened by the UK's Parliamentary Commissioner for Standards last week to determine if the British Indian leader had been "open and frank" in his obligation under the parliamentary "Code of Conduct".

Now, a full 'List of Ministers' Interests' published online reveals Rishi Sunak's reference to his wife's interests as well under a section entitled "Relevant interests of spouse partner or close family member".

"The Prime Minister's wife is a venture capital investor. She owns a venture capital investment company, Catamaran Ventures UK Limited, and a number of direct shareholdings," reads the register.

As a footnote, it adds: "As the Prime Minister set out in his letter to the Chair of the Liaison Committee on April 4, 2023, this includes the minority shareholding that his wife has in relation to the company, Koru Kids." Downing Street had maintained that rishi Sunak, 42, followed the rules of ministerial conduct at all times and had declared his wife's interests as a ministerial interest.

The publication of the register comes after a gap of 11 months when the last one was released and follows the Opposition's demands that the government come clean after the watchdog inquiry came to light.

Downing Street sources said the inquiry relates to Akshata Murty's interest in Koru Kids Ltd, which is likely to benefit from a new pilot scheme announced in the Spring Budget last month to incentivise people to become childminders.

Akshata Murty, the daughter of Infosys co-founder Narayana Murthy, is listed on the UK's Companies House register as a shareholder in Koru Kids - one of six childminder agencies in England listed on the government's website with contact details.

The Opposition had flagged this fact last month and called for further explanations at a hearing of the Liaison Committee - made up of all House of Commons committee chairs.

Labour MP Catherine McKinnell had asked Rishi Sunak if he had any interest to declare in relation to the new childcare policy.

"No, all my disclosures are declared in the normal way," he responded at the time. The parliamentary watchdog's investigation is to decide if there has been any breach of the code, which can then be put before MPs sitting on the Committee on Standards - which is responsible for deciding any sanctions.

"We are happy to assist the Commissioner to clarify how this has been transparently declared as a ministerial interest," a Downing Street spokesperson said earlier this week.

The UK's Parliamentary Commissioner for Standards is an independent officer of the House of Commons in charge of looking at evidence if individual British members of Parliament are feared to have broken a rule under the 'Code of Conduct'.