An owner has demanded action from Ascot and racing’s ruling body to ensure the scenes of fighting which have marred the past two Saturdays will not be repeated at the Royal meeting next month.

Matthew Lincoln, a syndicate owner involved in the Royal Hunt Cup contender Raising Sand, said on social media that the prospect of further violence means he is “seriously considering staying away” from the race meeting, forsaking the chance to see his horse take part.

“Racetracks need to invest in more robust security measures, which may even mean paying for a more significant police presence,” Lincoln told the Guardian. “It might sound drastic but how else are we to deter troublemakers?”

Lincoln made his comments after further footage emerged of a prolonged fight as racegoers left Ascot after racing on Saturday, security staff in hi-vis jackets being seemingly overwhelmed as a large group of men and women fought around them. Thames Valley Police has reported no arrests but urged witnesses to call with information.

There is a clear risk of further such scenes at Royal Ascot, where there was a widely reported brawl on Ladies Day in 2011 and another incident on the same day last year. Also at last year’s Royal week an unidentified racegoer threw a plastic pint glass full of beer at the jockey Andrea Atzeni as he rode to the start.

Ascot staff will meet police and other agencies this week to consider what improvements, if any, need to be made to existing security arrangements. “There are always things to learn after a raceday,” said the track’s Ashley Morton-Hunte, “and we will be reviewing everything and putting appropriate measures in place for Royal Ascot next month.

“Our annual preparation for Royal Ascot includes a scenario session, which will take place this week, as planned. Topical issues are discussed with relevant authorities and preventative measures will be agreed then.”

The British Horseracing Authority has encouraged racecourses to review their security needs in light of the Ascot fight and an even more worrying one at Goodwood the previous Saturday. “Whilst the incident at Ascot was quickly contained and smaller in scale [than the Goodwood fight], it shows the issues that courses face even with good planning and security precautions,” a BHA statement said.

“We have been in contact with the RCA [Racecourse Association] and we know courses will take into account the incidents as they make their security plans ahead of each meeting.”

Dermot Weld has a Derby contender once more, his Hazapour having defied odds of 16-1 to win Leopardstown’s trial race on Sunday. The chestnut colt, who beat two Aidan O’Brien-trained runners, is out of a half-sister to Harzand, who won the Epsom Classic for Weld two years ago. “So there’s only one logical way to go,” the trainer said of his charge, who is now third in the Derby betting at 16-1 behind the hotly fancied Saxon Warrior.

The French 1,000 Guineas was switched to Longchamp’s outer course after jockeys complained that the inner course was not safe. Particular concern was raised by an incident in the 2,000 Guineas in which U S Navy Flag, ridden by Ryan Moore, appeared to trip before fading out of the places. The 1,000 was won by Teppal, providing a first taste of Classic success for her trainer, David Simcock.