Kirit Kumar Chaman Lal Kundaliya v. Union of India and Ors. (1981) 2 SCC 436

Once the documents are referred to in the grounds of detention it becomes the bounden duty of the detaining authority to supply the same to the detenu as part of the grounds or pari passu the grounds of detention.

Golam alias Golam Mallick v. State of West Bengal (1975) 2 SCC 4

No doubt, Clause (5) of Article 22 of the Constitution and Section 8 of the Act do not, in terms, speak of 'particulars' or 'facts', but only of 'grounds' to be communicated to the detenu. But this requirement is to be read in conjunction with and subservient to the primary mandate: "and shall afford him the earliest opportunity of making a representation against the order", in the aforesaid Clause (5). Thus construed, it is clear that in the context, 'grounds' does not merely mean a recital or reproduction of a ground of satisfaction of the authority in the language of Section 3 of the Act; nor is its connotation restricted to a bare statement of conclusions of fact. It means something more.
That 'something' is the factual constituent of the 'grounds' on which the subjective satisfaction of the authority is based. All the basic facts and material particulars, therefore, which have influenced the detaining authority in making the order of detention, will be covered by "grounds" within the contemplation of Article 22(5) and Section 8, and are required to be communicated to the detenu unless their disclosure is considered by the authority to be against public interest.

Ganga Ramchand Bharvani v. Under Secretary to the Government of Maharashtra and Ors. (1980) 4 SCC 624

The mere fact that the grounds of detention served on the detenu are elaborate, does not absolve the detaining authority from its constitutional responsibility to supply all the basic facts and materials relied upon in the grounds to the detenu. In the instant case, the grounds contain only the substance of the statements, while the detenu had asked for copies of the full text of those statements.

Thahira Haris etc. Vs. Government of Karnataka and Ors., Decided by SC on 15.04.2009

The right which the detenu enjoys under Article 22(5) is of immense importance. This Article of the Constitution can be broadly classified into two categories: (i) the grounds on which the detention order is passed must be communicated to the detenu as expeditiously as possible and (ii) proper opportunity of making representation against the detention order be provided.
Our Constitution provides adequate safeguards under clauses (5) and (6) of Article 22 to the detenu who has been detained in pursuance of the order made under any law providing for preventive detention. He has right to be supplied copies of all documents, statements and other materials relied upon in the grounds of detention without any delay. The predominant object of communicating the grounds of detention is to enable the detenu at the earliest opportunity to make effective and meaningful representation against his detention.

Ram Krishan Bhardwaj v. The State of Delhi and Ors. 1953 SCR 708

Preventive detention is a serious invasion of personal liberty and such meager safeguards as the Constitution has provided against the improper exercise of the power must be jealously watched and enforced by the Court.
We are of opinion that this constitutional requirement must be satisfied with respect to each of the grounds communicated to the person detained, subject of course to a claim of privilege under clause (6) of Article 22.