Although the man died last year, the son has also renewed his father's membership of the Seville club for this season which entitles the milk carton containing the ashes to a seat in the Benito Villamarin stadium, according to one of the club's directors, Jose Antonio Gonzalez Flores.
However, not all has been a bed of roses for the dead man whose identity, and that of his son, have not been divulged.
According to the daily paper, El Mundo, although the son had no problem renewing the dead man's membership, he initially tried to take the ashes to the games in a glass container - a grave mistake.
After several weeks he was stopped by security officials who claimed the container constituted a dangerous object and as such was prohibited.
It was then, El Mundo said, that the son got the idea of placing the ashes in a one-litre, used Tetra Brik milk carton, a decision which met with the approval of the club's security officials.
Betis, one of Spain's oldest clubs, lie eighth in the 22-team First Division and are through to the last 16 of the Uefa Cup.
The club have 31,500 club members, most of whom are believed to be alive.Reuse content