The record-low attendance at the Under-20 World Cup could damage Turkey's chances of hosting major tournaments, including the 2020 Olympics and the 2024 European Championship, FIFA said on Friday.

With only Saturday's final and third-place match remaining, the turnout has averaged only 5,230 spectators over 50 matches, by far the lowest figure in the 36-year history of the competition. The next lowest was an average of 9,667 in the Netherlands eight years ago.

Jim Boyce, the chairman of the FIFA tournament organizing committee, called the many empty seats ''one negative point.''

''Turkey has proved that they can organize very smoothly from all other aspects of a major competition,'' Boyce said. ''So I honestly hope that does not have an adverse effect on the future. But it is still disappointing.''

Servet Yardimci, head of the local organizing committee, announced an investigation into the poor turnout.

''We are working on this issue. This is a very disappointing result. There must be reasons for this,'' Yardimci said. ''We are trying to find out the reasons and how we can learn a very important lesson.''

Before FIFA's second biggest competition after the World Cup kicked off, Boyce said the 23-day event was a showcase for Turkey and its potential to host major tournaments.

''It's very important the Turkish football public come out and give great support to this tournament,'' Boyce said in June.

The low turnout could affect Istanbul's chances in its battle against Madrid and Tokyo for the right to host the 2020 Summer Olympics, as well as Turkey's possible bid for the Euro 2024 tournament.

''I know that they are keen in the future to host a European Championship and, who knows, also the World Cup,'' Boyce said. ''I know how passionate the Turkish football fans are. But for some reason we did not get in the anticipated number of fans at the stadiums.''

Also, Boyce mentioned worldwide TV coverage ''showing very small numbers of people attending. I don't think that helps the situation.''

Istanbul is vying with Madrid and Tokyo for the 2020 Olympics, with the IOC to select the host city on Sept. 7 in Buenos Aires.

The Istanbul bid committee said the low attendance at the U20 tournament was ''the exception rather than the rule in Turkey.'' It said other recent sports events in Turkey - the Mediterranean Games, swimming short-course world championships, world indoor athletics championships and 2012 WTA Championships - ''have been well-attended across all sessions, with the venues often sold-out.''

''The Olympic Family can be assured that venues at a 2020 Olympic Games in Istanbul will be full,'' the bid committee said in a statement.

For the national football federation, the U20 World Cup has been ''the largest organization in Turkish sports history,'' according to Yardimci.

''This was a very important trial for the TFF. It could be very important for 2024,'' Yardimci said. ''We had the lowest number of spectators although we presented children and families with free tickets. We will find the reason.''

Yardimci said the tournament's timing in summer may have kept fans away from the stadiums in the seven host cities.

''They do like their own club teams rather than football,'' Yardimci said. ''They are not showing their interest in football as a whole.''

For FIFA, the low attendance put a stain on an otherwise successful tournament.

''Football has been the winner,'' Boyce said. ''There have been some fantastic games, last-minute goals, penalty shootouts, and an average 2.98 goals per game. The coaches deserve a lot of credit. They have encouraged their teams to really play football. The people who didn't turn up missed something.''