Indian IT services company Infosys, in which the chancellor Rishi Sunak’s wife owns an estimated £690m stake and collects about £11.5m in annual dividends, is “urgently” closing its office in Russia.

Infosys’s decision to shut its Moscow office comes as pressure mounts on Sunak to answer accusations that his family is collecting “blood money” dividends from the firm’s continued operation in Russia despite the invasion of Ukraine.

A source at Infosys told the Guardian that the company was “in the process of urgently closing down its Russian operation” and “relocating staff to other countries”.

An Infosys spokesperson declined to comment, and would not be drawn on whether the decision to close the Russian office was linked to the political pressure on Sunak.

Sir Keir Starmer, the Labour leader, earlier on Friday called on the chancellor to reveal whether his family had been “benefiting from money made in Russia when the government has put in place sanctions” on firms and individuals following Vladimir Putin’s invasion of Ukraine.

Sunak, who has repeatedly called on British companies to pull out of Russia in order to “inflict maximum economic pain” on Putin’s regime, had refused to comment on his wife Akshata Murthy’s 0.91% stake in Infosys.

Speaking to the BBC’s Newscast after a challenging week in which his spring statement met with heavy criticism, he said it was “very upsetting and … wrong for people to try and come at my wife”.

Sunak drew parallels with Will Smith, who hit the comedian Chris Rock at the Oscars on Sunday after a joke about his wife, Jada Pinkett Smith, as well as the beleaguered England cricket captain, Joe Root.

The chancellor quipped: “Someone said, ‘Joe Root, Will Smith, and me – not the best of weekends for any of us.’ But I feel, on reflection, both Will Smith and me having our wives attacked – at least I didn’t get up and slap anybody, which is good.”

Murthy, who keeps a low public profile, is the daughter of the billionaire founder of Indian tech giant Infosys. According to its latest annual report, Murthy holds a stake in the firm worth approximately £690m, which is estimated to have yielded £11.5m in dividend payments over the past year.

Labour and the Liberal Democrats have criticised Sunak over his wife’s investment in the firm, with the shadow transport secretary, Louise Haigh, calling it “really quite shocking”.

Asked about such comments, Sunak said: “You know, I think it’s totally fine for people to take shots at me. It’s fair game … [But] it’s very upsetting and, I think, wrong for people to try and come at my wife.”

He also defended his father-in-law, the Infosys founder NR Narayana Murthy, saying he had “nothing but enormous pride and admiration for everything that he’s achieved, and no amount of attempted smearing is going to make me change that because he’s wonderful and has achieved a huge amount. As I said, I’m enormously proud of him.”

While the UK government has ratcheted up sanctions on hundreds of Russian businesspeople and politicians close to Putin’s regime, the Indian government has been more ambivalent in its attitude to the invasion.

Infosys had continued to operate in Russia despite most big global IT and consultancy firms such as Accenture, KPMG, McKinsey, Oracle, PwC and SAP all closing their Russian operations.

Earlier this week, Infosys said it had “a small team of employees based out of Russia, that services some of our global clients, locally”. “We do not have any active business relationships with local Russian enterprises,” the company said, adding that it had committed $1m (£760,000) to help the victims of the war.

The ministerial code says that ministers must declare any financial interests that could give rise to a conflict, including those of their spouse and close family. A spokesperson for the chancellor has said Murthy and her family members did not “have any involvement in the operational decisions of the company”.