They were freed by magistrate Juliana Mohamed this morning on a technicality - the nature of their offences was not specified in their charge sheets.
The recharge was to allow the prosecutors to make proper amendments to the original charge.
Under the Police Act 1967, police have to specify the nature of the offences for those arrested under Section 27 which deals with police power to regulate assemblies, meetings and processions.
Twenty of them, including PRM vice-president Sivarasa Rasiah and secretary-general Sanusi Osman, Hulu Kelang state assembly representative Azmin Ali, Keadilan information chief Ruslan Kassim, youth member Abdul Ghani Haroon and PAS central committee member Hatta Ramli were recharged with illegal assembly at the National Mosque between 1.30pm and 5.13pm on Sept 19, 1999.
Meanwhile, Azmin, Abdul Ghani, cartoonist Zulkiflee Anuar @ Zunar and three others were also charged for a separate illegal assembly at Jalan Tun Tan Cheng Lok at 3.30pm on Sept 11, 1999.
The reformasi supporters were protesting over allegations that former deputy prime minister Anwar Ibrahim had been poisoned with arsenic while in detention after his sacking in 1999 as well as against the new restrictions imposed on PAS organ Harakah.
If found guilty, offenders can be fined up to RM10,000, jailed up to a year, or both.
Today's release and re-arrests of the 24 followed the same pattern of another court case earlier this year.
On April 13, High Court judge Zulkefli Ahmad Makinuddin ruled that the original charge of five reformasi activists was defectively framed as the prosecution had failed to state the specific offence.
The five were Keadilan vice-president Tian Chua, party Youth chief Mohd Ezam Mohd Nor, Youth leader Lokman Nor Adam, supreme council member Saari Sungib, party leader Dr Badrul Amin Bahron and social activist-cum-malaysiakini columnist Hishamuddin Rais.
Later, on July 18, the Magistrate's Court recharged five other activists of the same offence after they were discharged not amounting to an acquittal.
They are currently serving a two-year detention under the Internal Security Act at the Kamunting detention camp in Taiping, Perak.
Meanwhile, both cases have been fixed for mention on Oct 8 where the 24 re-arrested today as well as the other five ISA detainees are expected to be jointly charged.
The group of 24 activists was represented by lawyers Rajiv Prabakharan, Asmet Nasruddin, Saiful Izham, LY Chong, Abdul Kadir Ismail and Rashidah Mat Nawi.
Deputy public prosecutors S Devanandan and Fatimah Zahari represented the prosecution.