The Taliban issued a video on Sunday showing the beheading of a Polish geologist in Pakistan.
The tape showed two masked men cutting off his head.
Piotr Stanczak, 42, was kidnapped by armed men on 28 September in the town of Attock, about 65km west of the capital, Islamabad, where he was working for a Polish energy company.
His two drivers and bodyguard were killed.
The Taliban says he was killed because Pakistan's government refused to release 60 Taliban prisoners.