In Tilokchand Motichand'a case, the petitioners before this Coutt had realised several amounts from their customers outside Bombay eel acoount of sales tax. The Sales Tax Officer, by his order dated March 17, 1958, forfeite<f the same Wider s.21(4) of the Bombay Sales Tu: 8 Act, 1953. On March 28, 1958, the petitioners filed a writ petition in the High Court of Bombay seeking a writ ctf _mandamus_ restrainin: the Sales Tax Officer from recovering the amount from them on the ground that s. 21 ( 4) was _ultra vires_ the powers of the State LegislatUre and that the order of forfeiture was violative of Articles 19(1)(f) and 265 cJ the Constitution. On November 28, 1958, the writ petition was dismissed by a learned Single Judge on the ground that the peti~ _C_ tioners, having defrauded other persons, were not entitled to any relief. The appeal filed against the said order by the petitioners was dismissed on July 13, 1959. Before the appeal was dismissed, the Collector of Bombay attached the petitioners' prcperties at¢ the petitioners paid the amount to the Collector of Boml:iay between August 3, 1959 and August 8, 1960. In Kantllal Babulal & Bro.r. v. H. C. Patel(l) de· clded on September 29, 1967, tbis Court struck down s. 12A(4) of D the Bombay Sales Tax Act, 1946 as violative of Article 19 ( 1 ) (!) . The petiticners thereupon filed a writ petition under Article 32 of the ~onstitution on February .9, 1968, claiming refund of the amount paid by theni under s. 72 of the Indian Contract Act, 187Yon the &round that they paid the amount under a tnistake of law and that they discovered the mistake oitly when this Court struck down s. 12(A)(4) of the crnbay Sales tax Act, 1946. The petitioners also alleged that E ifiey paid the aniouiit to the collectOr under coercion ~d they were entitled to recover the same. The contention of the petitionerS wa;, for the grounds cin which this Court struck down s.12A(4) of the Bombay Sales Tax Act, .1946, s.21 (4) of the Boml;>ay Sales Tai ACt, 1953; was also liable to be stnick doWn. It was in these circumstana!'8 that this Court h to consider the question whether the petitiOmn ' :;::tm~ ,}fer~~~~uoi~~:tra: ~ rru~~:2eC::ti:~ ~ · . fore it shffii1t1 be disriU8sed. maayatbllah, C.J: observed :