Islamabad  - Taliban militants in troubled north-western Pakistan said Saturday that a Polish electrician held by them for the last 18 weeks has been beheaded.

A Taliban spokesman who identified himself as Mohammad, told various media organizations over the phone that Polish citizen Peter Stanczak was executed in tribal district of South Waziristan after the expiry of a February 6 deadline given to Pakistani and Polish governments to fulfil the militants' demands.

According to Mohammad, Taliban had initially demanded the release of their 61 comrades during the talks with the government through mediators. Later on, the numbers were cut down to 26.

He told BBC Urdu Service that the Pakistani government promised to release four Taliban fighters as a goodwill gesture by February 4, but it never fulfilled the promise despite a two-day extension in the deadline.

Gunmen ambushed Stanczak's vehicle in Attock district, about 85 kilometres from the capital Islamabad, on September 28. They killed his driver and two guards before snatching the man.

Fakhr Sultan a district police officer in Attock, said he had no information about the execution of Stanczak and nor any clue that Taliban had set some demands for his release.

A spokesman for Pakistan's Interior Ministry was not available for comments.

Stanczak worked for Poland-based Geofizyka Krakow Limited, which is exploring natural resource reservoirs in the region.

In October, militants released a video in which Stanczak asked the government to release some Taliban fighters from custody.

Islamic militants have intensified attacks on foreign diplomats and aid workers in recent months to avenge military operations against them. But secular nationalists are also carrying out such action for their demands in south-western region of the country. (dpa)