Ukraine's ambassador to the US, Olha Stefanishyna, is set to leave her post less than a year after arriving in Washington, as a controversy over her family's purchase of a luxury Kyiv apartment adds to mounting political pressure on President Volodymyr Zelenskiy's administration, Hromadske reports.

Stefanishyna's departure comes as Zelenskiy launches a broad reshuffle of his government and diplomatic corps aimed at strengthening Ukraine's relations with key international partners, particularly the US, while also navigating a series of domestic political challenges.

The former deputy prime minister and justice minister has been under scrutiny since an investigation by Ukrainian investigative outlet Hromadske alleged that her mother acquired a three-bedroom apartment in central Kyiv at a fraction of its market value.

According to the investigation, Nadiya Kravets purchased the roughly 100-square-metre apartment in the prestigious Lvivska Ploshcha residential complex in autumn 2022 for UAH3.04mn ($83,000). Journalists estimated that comparable apartments in the same development were selling for approximately UAH12mn, or about $300,000, at the time.

A real estate agent interviewed by Hromadske described the purchase price recorded in official documents as "unrealistic", saying apartments in the area were changing hands for no less than $2,000 per square metre.

The investigation also alleged that the property was not included in Stefanishyna's official asset declaration.

Stefanishyna has denied any wrongdoing.

In an interview with the investigative journalism project Bihus.Info, she said her parents had committed to purchasing the apartment in 2019, before prices surged, and that the transaction had been financed through a long-term instalment plan rather than a conventional purchase completed in 2022.

The ambassador has not been formally accused of any offence, and Ukrainian authorities have not announced criminal charges relating to the property transaction. However, Ukrainian media have reported that anti-corruption investigators have been examining the case, making it politically awkward for Kyiv's most senior diplomat in Washington.

The controversy comes at a particularly sensitive moment for Zelenskiy after the president announced a sweeping shake-up of his administration on July 12, asking Prime Minister Yulia Svyrydenko to resign after just one year in office.

Svyrydenko is reportedly going to replace Stefanishyna as ambassador to Washington. Zelenskiy is coming under increasing pressure as corruption investigations into his administration metastasise. The scandals started with a $100mn kickback  Energoatom corruption scandal, which has touch most of the senior officials in Zelenskiy’s administration. A recent poll found that most Ukrainians are more worried about corruption in the government than they are about the war with Russia.

Interfax-Ukraine previously reported that Stefanishyna had requested to leave the diplomatic service voluntarily, citing personal reasons. People familiar with the presidential administration, however, told the Financial Times that her departure coincides with the ongoing investigation into the apartment purchase.

Although Ukraine has made significant progress in strengthening anti-corruption institutions since 2014, Western governments have repeatedly stressed that continued reform remains a prerequisite for eventual EU membership and for sustaining long-term international financial assistance.