id the court is "studying the power vacancy" and "will take a few days".
There is uncertainty over who is going to take over the presidency after Mr Nkurunziza died on Monday aged 55 after suffering a cardiac arrest
The late president was preparing to hand over power to the president-elect, Major General Evariste Ndayishimiye in August.
According to the constitution, if the head of state dies in office then the speaker of the national assembly, currently Pascal Nyabenda, should succeed him.
Meanwhile, the government has denied reports that the mother of the late president has also died.
Mr Ntahorwamiye said Mr Nkurunziza's mother “is sick but not dead”. He added that the nature of her illness was a private matter.
The denial was prompted by social media speculation on her state.
The country's first lady returned home on Tuesday evening from Kenya where she had been hospitalised.