Abuja - President Muhammadu Buhari suspended his head of immigration Friday, the government announced, with the department under investigation over the approval of a visa to a fugitive radical Islamic preacher.
Ahmad al-Assir, wanted in Lebanon over deadly clashes with the army there, was arrested on Saturday as he tried to board a plane from the Middle Eastern nation to Nigeria using a fake Palestinian passport with a valid visa.
"The Comptroller-General of Nigeria Immigration service, Mr David Shikfu Parradang, has been suspended from office with immediate effect," Nigeria's interior ministry said in a statement.
No reason was given for the move, but news that Assir had received the green light to travel to Nigeria caused outrage in the west African nation, and made front page headlines.
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The Nigerian government launched an investigation into the affair earlier this week, although it was unclear if Parradang was being held personally accountable.
Assir had been on the run since June 2013, when he and some supporters fought a deadly battle with the army outside the southern Lebanese city of Sidon.
The army seized his headquarters after 48 hours of clashes that killed 18 soldiers, but Assir was able to escape with several of his followers.
He has continued to issue audio statements while on the run, and various rumours circulated as to where in Lebanon he was hiding.
In 2014, prosecutors sought the death sentences for Assir and 53 others, including singer-turned-fundamentalist Fadel Shaker.
They were accused of having formed armed groups that killed soldiers, and of having explosive materials, light and heavy weapons that they used against the army.
Assir, a native of Sidon and a Sunni Muslim, was virtually unknown politically before the outbreak of Syria's civil war in 2011.
He began making headlines after the conflict erupted by criticising Lebanon's powerful Shiite movement Hezbollah and its ally, Syrian President Bashar al-Assad.