A member of the Nigerian Islamist sect behind a deadly uprising in July has confessed to receiving military training in Afghanistan, police say.
The member of the sect known locally as Boko Haram and Taliban said he had been paid $5,000 (£3,000) to do the training and promised $30,000 on his return.
The uprising in northern Nigeria left some 700 people dead, mostly militants.
If confirmed it will be the first proven link between Islamists in the oil-rich country and Afghanistan.
Local people called the group Taliban because of the radical beliefs.
For years Western diplomats have feared an al-Qaeda sleeper cell might launch attacks on oil infrastructure in Nigeria, which is an increasingly large supplier to the US.