SINGAPORE - The police have issued a stern warning to a male Singapore student below 16 years old who posted a fake announcement on the supposed death of former prime minister Lee Kuan Yew on March 18.

In a statement issued on Tuesday, a spokesman said the police had completed investigations into the case.

Acting alone, the student had circulated online a screenshot photograph, purportedly from the Prime Minister's Office (PMO) website, announcing the death of Mr Lee.

Sparking an outcry among Singaporeans, it also fooled international news outlets such as CNN and Chinese broadcaster CCTV into prematurely reporting about Mr Lee's passing.

"The Police have completed investigations into the case reported on 18 March 2015 where a fake screenshot photograph of a statement purportedly from the Prime Minister's Office (PMO) website was circulated. The culprit is a male Singaporean student below 16 years of age. In consultation with the Attorney-General's Chambers, the Police have issued him with a stern warning in lieu of prosecution," the statement said.

Further details in a separate statement issued by the Attorney-General's Chambers (AGC) revealed that no "hacking" or unauthorised access of the PMO website had taken place. It also explained that the student had never intended for his message to be so widely disseminated.

"He created the image because he was frustrated with the frequent rumours about the demise of Mr Lee. He wanted to demonstrate to his friends how easy it was for a hoax to be perpetuated," said the AGC statement.

After sharing it with his friends, however, the image was quickly forwarded by one or more of the original recipients despite the student informing them that it was a fake.

The AGC added that the decision to issue a stern warning to the student, which was done in the presence of his parents, was taken after "careful consideration of all relevant factors" including his personal circumstances and readiness to accept responsibility.