England's Lesley Vainikolo, right, is tackled by Scotland's Dan Park in this March 2008 file photo. (AP Photo/Peter Morrison, File)
The 29-year-old Vainikolo, nicknamed The Volcano for his powerful build and speed on the field, was questioned by local police following a fight outside a nightclub early Sunday in Bath, southwest England.
The victim of the assault was released from the hospital soon after.
Vainikolo, who has played five times for England, was arrested but was not charged and has been released on bail.
He scored two tries for Gloucester in Saturday's 25-20 win over Newport Gwent Dragons in the Anglo-Welsh Cup.
Gloucester said it was aware of the incident but would make no comment while police were investigating the incident.
