A closure means for containing fluid leaking from a ruptured pipe comprising: a first and second housing member connected by a hinge and suitable for placing on a surface of a pipe to define an enclosed cavity between the first and second housing members and the surface of the pipe, and a fastening means coupled to the housing, characterised in that the fastening means is a clasp operable to hold the first and second housing members in a fully closed position in sealed engagement with the pipe to produce a sealed joint therebetween, and wherein the fastening means comprises a clasp arm coupled to the second housing member by two linkages (56a, 56b) pivotally connected to two retaining lugs (58a, 58b) on the second housing member and pivotally connected to a pivotal connection on the clasp arm, wherein the clasp arm is split into two portions: a lever extending in a direction away from the pivotal connection with the linkages (56a, 56b) and a clasp latch extending from the pivotal connection in a direction substantially opposite to the direction of the lever, wherein the clasp latch is operable to engage with clasp arm retaining lips (51a, 51b) formed on the first housing member to hold the first and second housing members in the fully closed position in which the linkages (56a, 56b) extend from the second housing member away from the clasp arm retaining lips (51a, 51b), and wherein the clasp latch is further operable to engage with the clasp arm retaining lips (51a, 51b) formed on the first housing member to prevent the closure means from opening in an initial partially closed position which allows the closure means to be moved along the length of said pipe, wherein in the initial partially closed position the linkages (56a, 56b) extend from the second housing member towards the clasp arm retaining lips (51a, 51b). a first and second housing member connected by a hinge and suitable for placing on a surface of a pipe to define an enclosed cavity between the first and second housing members and the surface of the pipe, and a fastening means coupled to the housing, characterised in that the fastening means is a clasp operable to hold the first and second housing members in a fully closed position in sealed engagement with the pipe to produce a sealed joint therebetween, and wherein the fastening means comprises a clasp arm coupled to the second housing member by two linkages (56a, 56b) pivotally connected to two retaining lugs (58a, 58b) on the second housing member and pivotally connected to a pivotal connection on the clasp arm, wherein the clasp arm is split into two portions: a lever extending in a direction away from the pivotal connection with the linkages (56a, 56b) and a clasp latch extending from the pivotal connection in a direction substantially opposite to the direction of the lever, wherein the clasp latch is operable to engage with clasp arm retaining lips (51a, 51b) formed on the first housing member to hold the first and second housing members in the fully closed position in which the linkages (56a, 56b) extend from the second housing member away from the clasp arm retaining lips (51a, 51b), and wherein the clasp latch is further operable to engage with the clasp arm retaining lips (51a, 51b) formed on the first housing member to prevent the closure means from opening in an initial partially closed position which allows the closure means to be moved along the length of said pipe, wherein in the initial partially closed position the linkages (56a, 56b) extend from the second housing member towards the clasp arm retaining lips (51a, 51b).