In a statement, Lewis said threats and intimidation had no place in a democracy.
“It has been brought to my attention that an anonymous and threatening letter circulating in Clough and Seaforde, delivered to some households, which is designed to intimidate, makes reference to me and asks members of the local community to contact me,” he said.
“I wish to make clear that this correspondence has nothing whatsoever to do with me and I was unaware of its circulation until it was brought to my attention.
“I totally reject its contents and make clear my rejection of it.
“I have referred this matter to the PSNI.
“Threats and intimidation can play no part in the democratic process.
“As a local councillor I am always available to work for all my constituents and to help everyone with the issues of concern to them.
“Anyone with information on those responsible should contact the PSNI.”
BBC News NI has approached the PSNI for comment.