A five-year-old British boy has been reunited with his family after a 12-day kidnapping ordeal in Pakistan, after a relative paid a $168,000 ransom for his release.

Sahil Saeed rejoined his father at the British High Commissioner's home in Islamabad, Pakistan's capital, before boarding a plane to Manchester, northern England, on Thursday.

"I am completely overjoyed that I have been reunited with my son after such a long ordeal," Raja Naqqash Saeed said in a statement.

"Sahil is doing well, is in good spirits and can't wait to return to the UK to see his Mum, his family and join his friends back at school," he added.

Trio face charges

Saeed was abducted at gunpoint on March 4 at his grandmother's house in the town of Jhelum, 100km south of Islamabad, while preparing to fly back to Britain with his father.

Three people arrested in northern Spain on Wednesday in connection to the kidnapping are being questioned by a Spanish court.

The trio; two Pakistani men and a Romanian woman, are suspected of going to Paris and seeking the ransom paid for the boy, before returning to the Spanish town of Constanti, where they were detained.

Spanish police said they found mobile phones in the flat where the three had been staying, which had been used to contact Saeed's father, as well as £105,000
($168, 000) and 3,565 euros ($4,916) in cash, and a new computer.

Another Pakistani man was also arrested in Constanti while French police detained two family members of the man who went to Paris for being accomplices.

The police statement said two relatives of those detained in Spain were also arrested by French police in Paris.

British officials gave no details on exactly how Sahil, who was left in a field by his abductors on Tuesday, had been recovered.

Doctors confirmed the boy was in good condition, adding that he was under police protection and accompanied by British officials.

Kidnappings of Westerners are rare in Pakistan, but abductions of locals are common.