Indonesian police have dropped pornography charges against hardline Indonesian cleric Rizieq Shihab after failing to find the person who uploaded the images.

Rizieq, the leader of Indonesia's Islamic Defenders Front (FPI), has been in exile in Saudi Arabia since being charged in May last year.

The charges related to a purported online chat between Rizieq and a supporter, which included naked images of the woman.

Screenshots of the chat, including an apparent request from Rizieq for the explicit images, were shared on the internet last year.

Under Indonesia's anti-pornography laws it is illegal to view, store or share any images of explicit nudity, or to make anyone else be an "object or model" of pornography.

The same laws were used in 2010 to jail Indonesian pop star Nazril "Ariel" Irham after two homemade sex tapes leaked online.

One of the groups pushing hardest for Ariel to be locked-up was Rizieq's FPI, before he was himself charged under the same legislation last year.

Rizieq, who is married, has repeatedly denied the allegations, saying images of the chat are fake.

After dropping the case, police made no reference to the legitimacy or otherwise of the chat.

"There was a formal request to stop the investigation by [Rizieq's] lawyer," National Police spokesperson Brigadier General Muhammad Iqbal said.

"Then, after cross-examination by the investigators, the case was dropped, because, according to the investigators, they haven't found the uploaders [of the online chat]."

Rizieq Shihab (pictured right) with Indonesian businessman and politician Prabowo Subianto.

Earlier this month Rizieq was visited in Saudi Arabia by former military strongman and presidential hopeful Prabowo Subianto.

It is believed the meeting was set up to discuss pairing Prabowo with Jakarta Governor Anies Baswedan.

Anies replaced popular Christian Governor Basuki "Ahok" Purnama in 2016, after Ahok was charged with blasphemy.

As leader of the FPI, Rizieq was integral in gathering momentum for the protests against Ahok and the charges that led to him being jailed.

In a video message to supporters, Rizieq thanked his lawyers, his supporters and God for delivering the good news.

"And finally [thanks to] the Indonesian Government," he said.

"In particular the National Police of Indonesia. I appreciate them for giving my lawyers the original document ordering the case be stopped, so it could be passed on to me here in Mecca."

He also urged Indonesians to act peacefully, so as not to disturb national stability and security, in the upcoming local election and next year's presidential race.