Afghan President Ashraf Ghani suspended his minister for telecommunications and information technology on Monday while he is investigated over a levy on mobile telephone charges, officials said.

The removal of Communications Minister Abdul Razaq Wahidi adds to a lingering political crisis in Afghanistan, heightened in November when parliament passed no confidence votes against a number of ministers over poor performance and budgetary issues.

Yasin Sameem, a spokesman for the communications ministry, said the decision to suspend Wahidi was taken after an audit into the collection of a 10 percent tax on mobile phone topups imposed in 2015.

He said the president's office, which has declared the fight against graft as a top priority, felt the ministry had not cooperated sufficiently with an investigation into alleged corruption surrounding the levy.

"We are committed to accountability and the minister will wait for the findings of the investigation," Sameem said.

The mobile phone levy, which has raised millions of dollars for government coffers, was imposed as part of efforts to raise domestic tax revenue to make up for a gradual reduction in international donor aid in coming years.

While Wahidi's suspension will not immediately affect the day-to-day functioning of the government, it highlights the difficulties Ghani has had in pushing through major reforms of the economy while fighting the Taliban insurgency.

Ghani ordered ministers removed by parliament to remain in their posts until a Supreme Court ruling on the affair but the standoff underlined the weakness of the national unity government formed after a disputed election in 2014.