"The accused is linked to the bombing that took place in Abuja," Hein Louw, the magistrate overseeing the court proceeding, said.
Two car bombs exploded near a parade in Abuja marking Nigeria's 50th anniversary of independence on Friday, killing at least 10 people and injuring 36, according to police.
The attacks were claimed by Nigeria's main militant group, the Movement for the Emancipation of the Niger Delta (Mend).
Security experts believe Okah - who accepted a government amnesty last year after gun-running and treason charges against him were dropped - was at one time the brains behind Mend, although he has denied ever being its leader.
Meanwhile, Nigeria's secret service said it made nine arrests in connection with Friday's blasts.
"They all have direct links with Henry Okah, the incident and some unscrupulous prominent elements in society," Marilyn Ogar, the Nigerian State Security Service (SSS) spokeswoman told a news conference in Abuja.
She said the SSS had foiled a larger plot to detonate at least six car bombs in the "three-arm zone" made up of the presidential villa, parliament and the supreme court just days before last Friday's attacks.
"The despicable act of terrorism which eventually took place on October 1 was planned for Wednesday September 29 but was foiled as soon as information was received during the early hours of September
28," Ogar said.
"The over-riding objective of the group was to scare foreign visitors from attending the 50th anniversary celebrations."
A Mend statement signed by Jomo Gbomo - the pseudonym used by the group to claim previous attacks on Nigeria's oil industry - was emailed to media warning the area should be evacuated an hour before the Abuja bombs went off.
But Goodluck Jonathan, Nigeria's president, said investigations had revealed Mend members knew nothing about the attacks and they had been carried out by a small group based outside Nigeria, sponsored by "unpatriotic elements within the country".
Timi Alaibe, Jonathan's special adviser on the Niger Delta, was quoted on Sunday as saying Mend's leaders were co-operating with the government.
"Everyone in the structure knows Jomo Gbomo is Henry Okah. There is no Mend sitting anywhere in any camp. It's all Henry Okah, through and through," he was quoted as saying by the This Day newspaper.
Mend carried out attacks on oilfields and pipelines in the Niger Delta, home to Africa's biggest oil and gas industry, for years until accepting an amnesty in 2009.
It has said it is fighting for a fairer share of the natural wealth for the vast wetlands region, whose villages remain mired in poverty despite five decades of crude oil extraction.
But Mend has been severely weakened since its leaders and thousands of gunmen accepted an amnesty offer from Umaru Yar'Adua , the late Nigerian president, last year and disarmed. It is unclear who is running the group now.
Source: Al Jazeera and agencies