The legal team of Indonesia’s opposition leader on Friday demanded the annulment of the April general elections due to alleged irregularities.

Thousands of police officers were deployed to guard Jakarta's Constitutional Court where on Friday morning a hearing began into the opposition's complaints.

President Joko Widodo was declared the poll winner with 55.5 percent of the votes, but former military general Prabowo Subianto has claimed he won the elections but was denied victory through electoral fraud.

Constitutional Court Chief Justice Anwar Usman said in a televised speech that the court would not succumb to anyone, was not afraid of anyone and would not be influenced by anyone.

He added that the judges' only duty was towards the constitution as per their oath of office.

The head of Prabowo's legal team, Bambang Widjojanto, presented arguments including that of the incompatibility of the vice-presidential candidature of Widodo's running-mate, cleric Maruf Amin, who held posts in two government banking institutions during the same period.

Prabowo has repeatedly complained of massive and systematic irregularities in the vote counting - in which he received 44.5 percent support - and electoral lists, making allegations even months before the polls. Electoral fraud was ruled out last month by the Elections Supervisory Agency.

After the announcement of official results on May 21, the former general's supporters held massive protests in the capital, which were followed by two days of violent clashes in which nine people were killed, while hundreds were injured and more than 200 were arrested.

Indonesian police continue to investigate the deaths, which were attributed to live ammunition in at least one case, even though only rubber bullets were allowed, as well as local groups which they have accused of planning riots in order to destabilize the government.

On Tuesday, Prabowo urged his followers to not gather in front of the court, while the chief spokesperson of the National Police, Asep Adi Saputra, said that around 32,000 officers had been deployed to maintain security until the judges announce their decision.

This is the second time that Prabowo has challenged election results in the court, having lost a similar appeal after losing to Widodo in the 2014 elections.

The hearings are set to end on Jun. 24 and the deadline for the verdict has been set for Jun. 28.