South Africa’s highest court says it has granted the main opposition party the right to examine files on a corruption case against the nation’s president that was dropped in 2009.

In a landmark ruling Tuesday the Supreme Court of Appeal ordered the release to the Democratic Party of official documents on an arms deal that allegedly implicated President Jacob Zuma and landed a close adviser in jail.

The opposition party had demanded to know why corruption charges against Zuma were scrapped ahead of 2009 elections he won. It applauded Tuesday’s ruling but said it expected to be obstructed in its quest to reopen the case.

Zuma’s office said in a statement the ruling “is being studied” for its implications.