The former TV star was convicted in 2014 of assaults on youngsters and was released on licence in 2017.
Police and probation officials are investigating reports that convicted child abuser
Rolf Harris had entered the grounds of a primary school near his home and waved at pupils.
The former TV star was convicted of 12 indecent assaults in June 2014, including one involving an eight-year-old who wanted an autograph, two on girls in their early teens, and a catalogue of abuse against his daughter's friend over 16 years. One of the assault convictions was later overturned on appeal.
He was released on licence in May 2017.
According to the Daily Mirror, Harris went on to the premises of Oldfield Primary School near his home in Maidenhead on Tuesday afternoon to talk to a sculptor working in the grounds.
Head teacher Richard Jarrett told the paper: "We've got a wood sculptor working close to the road at the moment and Rolf Harris lives about three doors down from the school.
"He must have seen him (the sculptor) and come into the school area. He had no access to the children whatsoever.
"I went over and shook his hand and introduced myself. He explained what he was doing - that he was getting some wood from the sculptor. I said, 'You need to go'."
Thames Valley Police confirmed that officers had been called to the school at 3.15pm on Tuesday.
In a statement it said: "A report was made that a man was on the site of the school. An officer attended the scene but no offence was committed. No arrests were made."
The Ministry of Justice said it was looking at whether there had been any breach of Harris' release conditions.
A spokeswoman said: "When sex offenders are released they are subject to strict licence conditions and are liable to be returned to custody for breaching them.
"We are looking into these reports and will take appropriate action."