Kathy Griffin has branded Donald Trump a “bully” and said she was the victim of state censorship amid an ongoing row over a photo of the President's decapitated head.

“I am not afraid of Donald Trump. He is a bully,” she said, in her latest remarks on the controversy.

Attorney Lisa Bloom added: “The message is clear: criticise the President, lose your job.”

The comedian also said on Friday that she may be facing a Secret Service investigation for posing with a bloodied and detached Donald Trump head, an image that both Democrats and Republicans have condemned.

Ms Griffin has apologised for the photo shoot, saying that she “crossed the line”, but apparently there is still a possibility that she may have committed a crime.

Threats “knowingly and willfully” made against the president, president-elect, vice president or vice president-elect are considered a class E felony under federal law. That includes any “threat to take the life of, to kidnap, or to inflict bodily harm” upon those officials.

However, Ms Griffin’s photo mocking the President could also be considered protected speech, if the act “did not constitute a knowing and willful threat against the President,” according to the 1969 Supreme Court ruling Watts v United States.

At a press conference in which she again apologised for the photos, Ms Griffin said she has been contacted by the Secret Service, but did not provide further information about the probe or if she was co-operating, according to the Associated Press.

She said she would not refrain from mocking the President in the future.

Dmitry Gorin, a criminal lawyer representing Ms Griffin in the Secret Service investigation, said the shoot was parody and the comedian did nothing wrong.

Ms Griffin has been sharply criticised for the image, with some labelling her as an attention-hungry celebrity looking for a boost to her career.

At least four theatres have cancelled her scheduled performances, and Saturday Night Live star turned senator Al Franken withdrew an invite to Ms Griffin for an event promoting his new book, Giant Of The Senate.

“After hearing from many Minnesotans who were rightfully offended, I've come to the conclusion that it would be best for her not to participate in the event we had previously scheduled,” the Minnesota Democrat said.

He said what Ms Griffin did “was inappropriate and not something that should be anywhere in our national discourse”.

CNN fired the comedian from its New Year’s Eve programme, which she has co-hosted for more than a decade.

Mr Trump has also lambasted the photo, saying that Ms Griffin “should be ashamed of herself”.

“My children, especially my 11 year old son, Barron, are having a hard time with this. Sick!” the President wrote.