Pakistan Muslim League-Qaeda chief Chaudhry Shujaat Hussain's brother and son were detained and subsequently deported after landing at a London [Images] airport from Spain, where a group of Pakistanis was arrested last week for allegedly plotting a terrorist strike.

British authorities quizzed the PML-Q chief's younger brother Wajahat Hussain and son Shafay Hussain along with four others accompanying them at the Gatwick airport on January 22 following a 'tip-off' from the Spanish police, who suspected them to be accomplices of the 11 Pakistanis arrested in Barcelona, The News daily reported on Friday.

After questioning the six men who were detained under the UK's anti-terrorism laws, the investigators decided not to let them enter the London city and subsequently deported them to Pakistan by a PIA flight on Wednesday.

Quoting diplomatic sources, the report said the Pakistan High Commission in London sent a demarche to the Foreign and Commonwealth Office over the incident.

A senior British High Commission diplomat met Shujaat Hussain in Islamabad on Thursday and 'apologised' over the incident, a family source was quoted as saying.

The PML-Q chief said he was seriously considering legal action for the 'wrongful' detention of his family members and other Pakistani passengers accompanying them.

In a statement, the British High Commission in Islamabad said the six people were arrested from the Gatwick Airport on January 22 for questioning and were released the next day.

However, it said the detention and questioning did not affect the visa status of these people.

Pakistan Foreign Office spokesman Muhammad Sadiq said 'it is a very regrettable incident and it should not have happened. We are taking it up with the British authorities,' according to the daily.