Imran Khan awoke on Sunday as an inmate in the high-security Attock prison in Attock city but should have been in Adiala jail in Rawalpindi, according to the order issued by an Islamabad trial court that found the former Pakistan prime minister guilty in a corruption case.

Khan, 70, was arrested from his home in Lahore on Saturday shortly after being convicted and sentenced to three-year imprisonment in the Toshakhana corruption case.

According to the court order, additional district and sessions judge Humayun Dilawar ordered the Islamabad police chief to arrest the Pakistan Tehreek-e-Insaf (PTI) chief, instead it was the Punjab police that arrested Khan.

The court also ordered the Adiala jail superintendent to receive Khan, who was taken to Attock jail amid tight security.

The court order issued for the inspector general of police (IGP) Islamabad said: "This is to authorise and require you the I.G. Islamabad Police to arrest the convict Imran Khan Niazi son of Ikramullah Khan and to send him to Central Prison Adyala, Rawalpindi, for serving out the stated sentences," the Dawn newspaper reported.

"This is to authorise and require you the said superintendent to receive the said convict Imran Khan Niazi into your custody in the said jail, together with this warrant for serving out the stated sentences," said another court order issued for the Adiala jail superintendent.

However, Khan was neither arrested by the capital police nor detained at Adiala jail, the report said.

It quoted sources in Punjab police as saying that the Lahore police were alerted before noon and an order was given to them to arrest Khan shortly after the court verdict.

Therefore, a team of Lahore police constituted under the supervision of a senior police officer was put on standby, which then reached Khan's Zaman Park residence shortly after the verdict was announced, the sources added.

Instead of taking Khan to a state-run hospital for medical examination before shifting him to prison as ordered by the court, a senior police officer took Khan directly to Attock jail and handed him over to the prison's superintendent, the report said.

PTI spokesperson Zulifi Bokhari said on Saturday that Khan was shifted to Attock Jail in the city of Attock amid tight security.

Attock is located on the bank of the River Indus, with Khyber-Pakhtunkhwa province lying on the opposite bank of the historic river. It is also the last major town of Punjab province along the Grand Trunk Road.

Attock prison is the same jail where former prime minister Nawaz Sharif was kept after his arrest following the toppling of his government by former president Pervez Musharraf

Khan's close aide and former Pakistan foreign minister Shah Mehmood Qureshi on Saturday questioned the quick arrest of the PTI chief by police in Lahore.

"It is a cause of concern that as the verdict is just being announced and the news was aired on television, the police arrived at Zaman Park to take Imran Khan in. Were the police already informed about the nature and the decision?" he asked.

The court ruling on Saturday came as a blow to Khan and has put his political future in jeopardy. The verdict came as Pakistan is heading for general elections later this year, with the current National Assembly set to complete its term on August 12.

The case alleges that Khan "deliberately concealed" details of the gifts he retained from the Toshakhana, a repository where presents handed to government officials from foreign officials are kept, during his time as the prime minister and proceeds from their reported sales.

This is for the second time in three months that Khan has been arrested.

Earlier, he was arrested on May 9 in Islamabad from the high court's premises in the Al-Qadir Trust corruption case, sparking violent protests by his supporters.

Khan faces more than 140 cases across the country and charges like terrorism, violence, blasphemy, corruption and murder.