Kabul, Mar 1 (IANS): The Afghanistan special forces have detained a German national who had been fighting along with the Taliban for almost a year, officials said on Thursday.

The operation, in which another two Taliban insurgents were also detained, was conducted on Wednesday night in Greshk district in Helmand province, Abdul Qayum Nuristani, spokesperson for the Afghan National Army-Special Operation Corps told Efe news.

"The German national has been detained along with other Taliban fighters by commandos from the 7th Battalion in Greshk of Helmand in a Taliban base," said Nuristani.

He added that according to initial reports, the German had been in Afghanistan for nearly one year.

Security forces also recovered documents that confirmed his identity as well as his involvement with the Taliban, the spokesperson said.

"He was a Taliban member and was directly fighting for them against Afghan forces," he said.

The man, whose identity was not revealed, said he had been living in the country for about a year and called himself "muhajir", a term used for Muslims who flee their country of origin in the wake of atrocities to take refuge in an Islamic country.

Afghan Defence Ministry spokesperson Dawlat Waziri also confirmed the German national's arrest and said that several Taliban hideouts and ammunition depots were destroyed in the special operation.

Helmand Governor's spokesperson Omar Zwak said that an investigation into how a foreign national joined the Taliban, was underway.

Since the end of NATO's combat mission in January 2015, the Afghan government has been steadily losing ground to insurgents and now controls only 57 per cent of the country, according to the US Special Inspector General for Reconstruction of Afghanistan.