Italy has said “those responsible will pay” if reports that the daughter of the North Korea’s former ambassador to Rome was forcibly taken back to Pyongyang after her father went into hiding are correct.

Jo Song-gil and his wife fled the embassy in Rome without notice in early November, weeks before his mandate was due to end, raising suspicion of a defection of a senior North Korean official.

Thae Yong-ho, a former North Korean diplomat who defected to South Korea while serving as deputy ambassador to London in 2016, said the couple’s daughter – believed to have been attending high school in Rome – was repatriated before she made an attempt to reunite with her parents.

Thae told the South Korean news agency Yonhap: “I do not know for sure how many children Jo had, but the one who stayed in Italy has been sent back to North Korea. Jo is currently with his wife.”

In January, Thae called for Seoul’s help in bringing Jo to South Korea.

He added: “I can no longer publicly tell Jo to come to South Korea. The amount of punishment that is imposed to those whose family members fled to South Korea is incomparable to those whose family fled to other countries.”

Politicians with Italy’s Five Star Movement have called on their coalition partner, Matteo Salvini, the interior minister and leader of the League, to clarify the report.

Manlio Di Stefano, deputy foreign affairs minister, said that if the report was confirmed the case would have been of “unprecedented severity”.

“Those responsible will pay,” he added.

Maria Edera Spadoni, the vice-president of the lower house of parliament, said: “North Korean intelligence seized the daughter of the North Korean ambassador Jo Song-gil on Italian soil? This is a serious episode. Matteo Salvini must report to parliament as soon as possible.”

In January, South Korea’s JoongAng Ilbo newspaper reported that Jo had applied for asylum to an unidentified western country.

At the time, the Italian press reported that Italy had not received an asylum request from a North Korean official.

Jo, 48, had been acting ambassador in Rome since October 2017 after Italy expelled the previous ambassador, Mun Jong-nam, in protest at a nuclear test by North Korea in violation of UN resolutions.

North Korean diplomats serving overseas are often required to leave behind several family members – typically children – to discourage defections. However, Jo came to Rome in May 2015 with his wife and children, suggesting he may be from a privileged family.

The alleged repatriation comes as the US president, Donald Trump, and the North Korean leader, Kim Jong-un, prepare for their second summit, which is expected to be held in Vietnam at the end of February.