Businessperson Hugh Glenister was "shell shocked" by the Constitutional Court ruling that part of the legislation enabling the disbanding of the Scorpions and launch of the Hawks was constitutionally invalid.

"I am a little bit shell shocked. I was really not expecting this," Glenister told Sapa on Thursday.

The court ruled on Wednesday that the legislation was constitutionally invalid because it did not provide enough protection against political influence for the Hawks, a specialist investigative unit within the police.

It ordered that Chapter 6A of the South Africa Police Services Act 68 of 1995, as amended, be sent back to Parliament, with the order of constitutional invalidity suspended for 18 months, until it has been rectified.

Glenister took the case through the courts following a decision taken at the ANC's 2007 Polokwane conference that the Directorate of Special Operations, known as the Scorpions, be disbanded. The ANC had repeatedly accused the Scorpions of a political agenda as it tried to prosecute President Jacob Zuma for allegedly accepting a bribe facilitated by his former financial advisor Schabir Shaik and French arms company Thint.

After Shaik's conviction and sentence for corruption and fraud, the Scorpions pursued Zuma and Thint. This was however dropped due to interference in that investigation.

"I am full of the joys of spring," said Glenister, who had cut a lone figure chain smoking during the court recesses of previous hearings on the matter.

He lost several times. Plans went ahead to disband the Scorpions, who fell under the National Prosecuting Authority and justice department, and form the Directorate for Priority Crime Investigation, (DPCI) otherwise known as the Hawks, within the structure of the police.

"I can only hope, but I cannot predict, that South Africans will now start tightening the reigns on their politicians at every level, from the municipal to national."

At one point he considered giving up.

"But people were chirping in my ear and making me positive. When battling a lone battle there are times when you get despondent, you just want to walk away and say 'enough'. But human beings have the capacity to inspire others."

A Hawks spokesman said they would comment after seeing the judgment.

Deputy Justice Minister Andries Nel declined to comment and noted the court had directed itself at Parliament, not the justice department, to rectify the legislation.

"I think we would want the opportunity to study that judgment, but also ... the Constitutional Court has directed its order and its relief at Parliament to take action. So I think you should seek Parliament's views," Nel said.

In its ruling, the court explained that the Constitution, the Bill of Rights and international agreements on combating corruption, which had been approved by Parliament, required that states create independent anti-corruption entities.

The judges said the DPCI's activities must be co-ordinated by Cabinet, and that the statute provides that a ministerial committee may determine policy guidelines for the DPCI's functioning, and for the selection of national priority offences.

This makes the unit vulnerable to political interference, with inadequate safeguards.

"... Conditions of service of the unit's members and in particular those applying to its head make it insufficiently independent. Members thus have inadequate employment security to carry out their duties vigorously; the appointment of members is not sufficiently shielded from political influence; and remuneration levels are flexible and not secured. These aspects make the unit vulnerable to an undue measure of political influence."

The judges also found the Constitution does not oblige Parliament to place a specialised corruption-fighting unit only within the National Prosecuting Authority (NPA), where the Scorpions had been situated.

During the Zuma investigation the NPA was dogged by controversy. One of its heads, Bulelani Ngcuka, eventually left after a long-standing impasse over a statement that although they had prima facie evidence Zuma was guilty, they would not prosecute him.

Another NPA head Vusi Pikoli was subjected to an inquiry over whether he was fit to hold office after the unit attempted to arrest former national police commissioner Jackie Selebi, who is now in the process of appealing a 15-year corruption sentence.

Although the inquiry concluded it could not find he was unfit to hold office, he was fired by former president Kgalema Motlanthe.

Selebi maintained he was the victim of a plot by the Scorpions.