Former Peru forward banned from leaving Ecuador
Oblitas, a gifted winger who played for Peru in the 1978 World Cup, was coach of LDU, the reigning South American champions, from 2004 to 2006.
He is in Ecuador for a pre-season friendly with Sporting Cristal, the Lima-based team he now coaches.
"The SRI has prohibited Juan Carlos Oblitas from leaving the country for not paying taxes," said the SRI in a statement.
"Mr Oblitas has promised to pay the amount owed by today (Wednesday) but the SRI will keep in force this precautionary measure until he fulfils his obligations."
The case comes in the middle of a clampdown on tax evasion by the Ecuadorean government.
Oblitas, who was also in Peru's 1982 squad on the last occasion that they played in a World Cup, coached the national side from 1996 to 1999 when they enjoyed a relatively successful period.