The church of Casting Crowns drummer Andy Williams is asking people to pray after he had to have one of his legs amputated following a serious motorcycle accident.

Andy Williams was riding his motorbike to church on 27 June when he was hit by another vehicle.

His church, Grace Chapel in Franklin, Tennessee, said in a Facebook post that one of his legs has been amputated above the knee. 

He remains in critical condition, with his brain and other parts of his body also sustaining serious injuries.

Grace Chapel revealed that Williams has also undergone surgery to treat "continued fevers".

"The procedure was a success and doctors removed bacteria from his lungs," the church said.

"Pray that this will keep his temperature down and the fevers at bay as God continues to heal his body. Continue to pray for complete healing and for the amazing doctors who are working diligently."

A GoFundMe campaign set up by the church to cover medical costs has so far raised over $50,000. 

An update to the crowdfunding page on Thursday said Williams remains on a ventilator and "continues to fight", and that family and friends are meeting in the hospital courtyard every day to pray. 

"Thank you for your prayers, support and love. The family is overwhelmed with the support they have received and are continuing to receive. Your love for Jesus and for Andy is apparent. A million thanks," said the update. 

"At this point, The Lord has made it clear that we are to continue to pray for healing and for Him to move with, and beyond what the medical professionals can do.

The family is also requesting that as you pray for Andy to please remember the other families and patients on Andy's floor. So many are hurting and going through the same struggles and battles as them."