No ban on rainbow flags at NRL grand final

Sydney's ANZ Stadium has dismissed reports fans will be banned from flying rainbow flags at Sunday night's NRL grand final.

Security will be tight as fans arrive for the season decider between the Melbourne Storm and the Queensland Cowboys.

Politicians and activists from both sides of the gay marriage divide have weighed in after pre-game entertainment US rapper Macklemore revealed he would be singing his hit Same Love, a marriage equality anthem.

The singer stoked the flames by declaring on Saturday he will donate the Australian earnings from the song, which has returned to number one on iTunes in Australia, five years after it was first released, to the "yes" campaign in the postal vote.

Reports in the Daily Telegraph indicated fans would be searched to ensure no politically themed items, such as rainbow flags and 'yes' or 'no' signs would be brought in.

ANZ Stadium clarified on Sunday morning there was no ban on rainbow flags.

"Fans are encouraged to bring colour and energy to the event and are allowed to express their views," it said in a statement.

"Small flags and banners are permitted".

Fans wearing or displaying inappropriate or offensive logos may be denied entry, which is line with stadium policy for major events.

Team flags will be allowed, but they will be restricted to the official supporter zones at either end of the stadium.

Meanwhile, the NRL denies it has been unable to sell all the tickets to fill the 83,000-seat stadium.

Thousands of free tickets have reportedly been handed out, with sales dragged down by the lack of a Sydney team in the grand final.