One of Egypt's richest men has been accused of mocking Islam after tweeting cartoons of Mickey and Minnie Mouse wearing conservative Muslim attire.
Telecoms mogul and Coptic Christian Naguib Sawiris apologised for re-posting the images on Twitter a few days ago, saying he meant no offence.
But several Islamic lawyers have filed a formal complaint and there are calls for a boycott of his businesses.
The outcry comes at a time of tension between Egypt's Christians and Muslims.
There are also concerns about the growing influence of the ultra-conservative Salafists in Egypt. Salafists take their inspiration from the early generations of Muslims who were close to the Prophet Muhammad and his message.
The tweeted images showed Mickey Mouse wearing a traditional Islamic robe with a full beard, while Minnie Mouse is wearing a niqab - a full-body veil - with just her eyes showing.
She is identifiable by her large ears and trademark pink hair ribbon.
The cartoons were already widely circulating online, but when Mr Sawiris re-posted them last week, he received an immediate angry reaction from people who said they were offended.
On Friday, he tweeted: "I apologise for those who don't take this as a joke, I just thought it was a funny picture; no disrespect meant. I am sorry."
But tens of thousands of people have joined groups on Facebook and other social media condemning him.
"There's a fine line between expressing your opinion/freedom of speech and being flat out disrespectful," said one woman.
Shares in Mr Sawiris' telecoms company, Orascom - Egypt's largest private employer - have already fallen as a result of the row and subsequent calls for a boycott.
The prosecutor general's office said a group of Salafist Muslim lawyers had filed a complaint accusing Mr Sawiris of religious contempt.
"How can a man like this make fun of Muslims, in a country on the brink of sectarian discord," Muslim cleric Mazen el-Sersawi said in a television interview.
"If this is just joking, why don't you depict Mickey Mouse as a monk or a nun?"
Mr Sawiris, whose father is the richest man in Egypt, is a champion of secularism and has spoken out against the rise of Islamic fundamentalism in the country, including the increasing number of women wearing full-face veils.
He was a leading voice in the anti-government protests that ousted Hosni Mubarak from power in February and recently started a new political party, The Free Egyptians.
But many have questioned his wisdom in sharing the cartoons at a time of tensions between Coptic Christians and conservative Muslims.
Scores of people have been wounded and several killed in clashes between the two communities in recent months, and there are fears this row will increase the chances of more sectarian clashes in the run up to post-revolution elections in September.